The heat exchanger is used for exchanging heat energy between two fluids having different heat energy such as between the refrigerant gas and air. More specifically, it is used broadly for heating, cooling, evaporating, and condensing of the fluids by transferring heat efficiently from an object having high temperature to an object having low temperature. For example, such an heat exchanger is installed in the steam generator and the condenser of the boiler; in the indoor unit and the discharger of the air conditioner; in the radiator of the automotive part; and the like.
The heat pipe, which is an example of such a heat exchanger, is capable of heating or cooling the other fluid around the pipe such as air by tubing one fluid such as liquefied refrigerant gas in the pipe as a heat medium; and generating a heat cycle of evaporation (absorption of the latent heat) and condensation (release of the latent heat) of the refrigerant gas. In the process of this heat cycle, the other fluid performs heat transport.
At this time, by forming fine grooves in the pipe, the heat medium can be transferred by utilizing the capillary force of these fine grooves even in the absence of height difference between the one end (evaporating side) and the other end (condensing side) of the pipe, for example (refer Patent Literature 1 (PTL 1), for example).
In addition, a configuration, in which the heat medium is retained and transferred in the pipe by utilizing the capillary force between the fibers by laying braided fibers called the wick in the pipe, is known (refer Patent Literature 2 (PTL 2), for example).
In addition, a configuration, in which the heat medium is transferred by utilizing the capillary force between the fibers while a certain amount of the heat medium retained by laying sintered aluminum fibers in the pipe, is known (refer Patent Literature 3 (PTL 3), for example).